Equipment with mutually interacting spiral teeth

ABSTRACT

There is designed an equipment with mutually interacting spiral teeth, comprising at least two spiral rotors seating in a stator, where surfaces of the rotor shafts, a rotation wrapper of each of the rotors, each one being furnished with at least one spiral tooth, and a shape of the stator inner further are created by a rotation of a combination of curves having convex and/or concave shape, the curve waveform being defined by shapes of the spiral teeth profiles and their thread lead, provided the spiral teeth profiles and their thread lead, as presented in any section perpendicular to a longitudinal axis of the rotors, are created in relation to required values of pressure, volume and velocity of a media in any part of a working space within the section, the working space being defined as intermediate space between respective spiral rotors themselves and between the rotors and the stator, while the spiral teeth manifest leads of the same or opposite sense.

TECHNICAL FIELD

[0001] The invention relates to an equipment with mutually interactingspiral teeth, comprising at least two rotors and a stator with a workingarea determined by at least two spiral teeth, which are wound-up onshaft surfaces, thus creating the rotors, the spiral teeth having thesame or opposite sense of thread leads, a constant or variable leadangle and the spiral teeth wrapper is determined by a sum of profiles ofall sections through the spiral tooth by a rotation plane intersectingthe axis of rotation, while the axes of rotations of mutuallyinteracting spiral teeth are parallel or concurrent or skewed.

BACKGROUND OF THE INVENTION

[0002] Basic requirements on equipment with mutually interacting spiralteeth comprise either a change of a medium volume without or with asimultaneous increase of its pressure, or a change of pressure and/orflow rate at the output while maintaining the medium volume or anutilisation of a medium pressure energy without a change of the mediumvolume and conversion of the energy into a rotary motion or anutilisation of the pressure energy by simultaneous medium expansion andconversion of the energy on a rotary motion or expansion of a burningmixture of fuel and compressed medium volume and conversion of thepressure energy into a rotary motion by a simultaneous medium volumeexpansion.

[0003] There exist a plenty of well-known equipment operating on aprinciple of mutual interaction of spiral teeth wound-up on at least tworotors seating in a stator, or, as the case may be, wound-up on onerotor and on inner stator surface Spiral teeth surface can be by partsdescribed by functions given in any point by three parameters, i.e. by adiameter of a basic helix, by an angle of an angular displacement and byan angle of a helix lead. Each rotor can be represented by a determinedsum of profile sections running through co-axial rotating areas, usuallydefined as surfaces of second degree, namely a spherical surface, aconical surface and in limited values by a surface perpendicular to theaxis of rotation. The solutions known at present have spiral teeth whichare wound-up on a cylindrical or a conical shaft wrapper. Thesesolutions are known for different type of profiles of spiral teeth,nevertheless they do not enable a variability and especially steepnessof profile changes of the same spiral tooth along its axis. By rotorswith a shaft cylindrical wrapper it is possible to change the threadintermediate space only by a change of spiral teeth lead. At rotors witha spiral conical wrapper it is possible to change the threadintermediate spaces by a change of spiral teeth lead and by a change ofa vertex angle of the conical shaft wrapper. The change of volume ofspace between the threads is in both cases limited by the length and byrotors diameters. It is impossible to extremely increase the size ofrotors because the demands on built-in space do not increaseproportionally. Large masses can cause unbalances and oscillation ofrotors and problems with their sealing.

[0004] Known equipment for media compressing, like rotational spiralcompressors, work on a principle of rotors with cylindrical rotationalwrapper and with spiral teeth having a constant lead and a constantteeth profile. These rotors function only by transporting a mediumthrough thread intermediate spaces in the direction from input tooutput. The pressure is produced at the equipment output. Thedisadvantage comprise a limitation of a compression rate caused byequipment dimensions and by the construction as described above as well.The efficiency of the present equipment of this type is limited by aconstant shape and size of labyrinth of the thread intermediate spaces.

[0005] The equipment with a constant volume of a thread intermediatespace is also used as generators and in reversed arrangement as motors,e.g. pneumatic motors, hydro-motors, where a pressure medium is fed toan input and moves spiral rotors. The disadvantage comprise again aninvariable and steep characteristics of a pressure change performedbetween the medium input and output.

[0006] By a serial arrangement of the equipment there is acquired astaggered increase of compression, while a parallel combination of alarger number of the equipment provides for an increase of the volumecompression rate.

[0007] In principle as unsuccessful there can be depicted knownconstructions of internal combustion engines with spiral teeth. Thearrangement of such motors has been so far restricted to combinations oftwo and more mutually interconnected individual equipment, like acompressor and an expander. The disadvantage of these solutions consistmainly in limited possibilities of adaptation of a shape of a workingspace and arrangement of individual parts of equipment for suction,compression, expansion and exhaustion to a particularly requiredprocedure of an internal combustion process. All known equipmentmanifest large dimensions. The types with shafts and housing of acylindrical shape have mainly large overall length and at the types withconical shafts and housing have large diameters. Such parametersnegatively influence even a dynamic balancing of rotors.

[0008] Known equipment comprise for example a technical solutionaccording to CZ utility model No. 8308, where spiral teeth are wound-upon a conical body and a rotating wrapper of rotors is also a conicalone. In this type of equipment a change of a medium volume occursalready in a thread intermediate space, nevertheless process and degreeof compression and expansion of a medium is limited by vertex angles ofconical rotors. Such an embodiment cannot be modified so as to change aworking characteristic of the equipment as required.

[0009] There is also known a solution of a combustion motor with arotating disc as presented in CZ patent application PV 558-91,describing rotating compressor discs with thread surfaces splitting aworking space of a rotating working disc. However this thread surfacesare not in a mutual interaction and the rotating compressor discs serveonly as rotating slide valves of the working disc and do not transfer apressure force into a torque. The disadvantages of this solution includea periodic charge cycle and maximum pressure impacts applied on rotatingslide valves. The equipment requires perfect sealing. A wear of partsresulting from combined effects of mutually sliding movements andsimultaneously acting impact forces will be high and therefore theservice life of the equipment probably low.

[0010] Another similar solution of a rotating motor, included in a PCTpatent application WO 93/14299, is an equipment utilising a rotatingdisc for splitting a working space of a rotor with a spiral tooth, therotating disc being fitted with a notch allowing for a passage of thespiral tooth. The rotating disc and spiral tooth create two movablepartitions of the working space. Outer convex surface of the workingrotor is given by an outer shape of the rotating disc and do notdetermine working characteristics of the equipment. The rotating discspiral tooth is not in interaction with any other spiral tooth.

[0011] Another known solution, as described in a paper DE 19738132 A1 isbased on a principle of counter-rotating rotors with mutually adaptedteeth profiles, with cylindrical or tapered rotation wrappers of rotorsand with changing lead of spiral teeth of rotors. The compressionhappens already in the thread intermediate spaces, nevertheless thedegree of compression is limited by the equipment dimensions. A transferof a medium happens by a rotation of the rotors in mutually oppositedirections, the medium being compressed only in an intermediate space ofthese rotors, not in a space between the rotor and the equipmenthousing. The construction allows only for a certain maximum possiblelength of the spiral teeth and a certain minimum number of threads ofthe spiral teeth is necessary to make it work.

[0012] Another known solution according to U.S. Pat. No. 5,533,887 hastwo interacting rotors running in mutually opposite directions. The tworotors seating in a common housing, have tapered shafts on which thereare wound-up spiral teeth with a constant lead and rotational wrappersof the spiral teeth form have a shape of cones with an orientationopposite to that of the shafts. These rotation wrappers of the rotorsdefine tapered inner spaces of the housing with which they are also in amutual interaction. This construction provides for a surface sealing ofthe rotor spiral teeth against the housing and therefore the spiralteeth have identical lead depending on vertex angles of the taperedshafts and the housing, the angles determining a waveform of workingcharacteristics of the equipment. By the same input parameters it ispossible to obtain only corresponding output parameters. Thus anapplication variability of the equipment is significantly limited.

[0013] Another known design according to U.S. Pat. No. 2,908,226provides only for skewed rotor axis and the same sense of spiral teethlead and thus for the same sense of rotor rotation and a constant lead.Due to the constant teeth lead the teeth profile can be changed only bya design of the teeth side walls. To allow for a mutual rolling of theteeth, there is applied a recess in the teeth side wall, the recessbeing positioned in places where the profiles of adjacent teeth wouldoverlap and prevent any rotation. The shape of rotor profiles thusresults only from necessary basic mechanical requirements. The saiddesign is a mere spiral conveyor with a compression of transportedmedia.

[0014] There is also known a solution described in GB patent 419338. Theequipment, a spiral pump or a compressor is furnished with teeth havingonly trapezoidal profile. Tooth height to width ratio equalsapproximately one. Rotors may be equipped with spiral teeth with onlyopposite sense of lead. Rotational wrapper of the rotors is of a coneshape only, or may comprise several cones with different vertex anglesand with a staggered transition from one cone to the adjacent one.Therefore the teeth height and lead is changed only linearly. Only thetwo parameters are changed.

[0015] A solution according to GB patent 2 030 227 presents rotationalcompressor or a motor-generator powered by a pressurised media, themedium being preferably a gas. The design comprise two double spindlesconsisting of parts arranged into a spiral, the spindles of each pairbeing mirror-like arranged on a common shaft. The shafts may be only ina parallel arrangement. A rotational wrapper of the spindles has aconical shape and the spiral teeth have opposite lead with respect tothe rotor symmetry plane. The equipment provides for a compression of amedia from an input at one end towards a centre and expansion from thecentre towards output on the other end. Outside diameter of spiral teethis changed linearly, so the spindles are of a conical type andsimultaneously there is changed only the teeth lead. The teeth profilecan be adapted to the desired pressure input/output difference, but onlya continuous change can be achieved.

[0016] A solution according to paper DE 197 28 434, suitable only forapplications as a compressor or an air pump, may comprise only rotorswith parallel axis and spiral teeth having opposite sense of lead. Theconstruction provides for a change of a diameter and length of spiralteeth according to changing temperature to maintain clearance betweenrotors and a stator. Respective rotational wrapper of the rotors andstator inside surface are therefore defined only by one parameter,inside temperature.

[0017] Known constructions of mechanisms with spiral teeth of the abovediscussed type have been designed with respect to desired power at theoutput, mainly pressure or discharged volume as a final constant value.Only one or two dimension parameters have been selected as variables,while other dimensional parameters have become dependent values. Only ina case of possible limit value overrun, resulting from controlcalculations, there have been performed a correction and subsequentredesign of the mechanism shape. By a limited number of variables it isnot possible to select a desired pressure distribution as a controlparameter for design of shape and dimensions of the mechanism. None ofthe existing mechanisms provides for application of distribution of mainparameters, namely pressure, volume and temperature, characterisingstate of a media in any part of a working space of the mechanism, ascontrol functions for design of outside and/or inside shapes anddimensions of the mechanism. All so far known solutions allow forchanges of profiles of spiral teeth and for changes of spiral teeth leadonly in a restricted range. No particular exact requirements on mediaparameters like pressure, volume and velocity within inside workingspace can be applied.

DISCLOSURE AND OBJECT OF THE INVENTION

[0018] The foregoing problems are solved by an equipment with mutuallyinteracting spiral teeth, comprising at least two spiral rotors seatingin a stator, where at least a part of a rotation wrapper of each of therotors and corresponding parts of the stator inner surface and the otherrotor shaft surface are created by a rotation of a curve having a convexor concave shape, the equipment in accordance with the presentinvention, featuring surfaces of the rotor shafts, a rotation wrapper ofeach of the rotors, each one being furnished with at least one spiraltooth, and a shape of the stator inner further which are created by arotation of a combination of curves having convex and/or concave shape,the curve waveform being defined by shapes of the spiral teeth profilesand their thread lead. The said spiral teeth profiles and their threadlead as presented in any section perpendicular to a longitudinal axis ofthe rotors are created in dependence upon required values of pressure,volume and velocity of a media in any part of a working space within thesection, the working space being defined as intermediate space betweenrespective spiral rotors themselves and between the rotors and thestator, the spiral teeth having leads of the same or opposite sense.Further in accordance with the present invention the axis of shafts ofthe spiral rotors are located in one plane or alternatively may bemutually skewed. Still further in accordance with the invention therotation curve in at least in one of its parts may comprise a convexcurve, while at least in one of the remaining part it is of a concavetype.

[0019] On the contrary to existing mechanisms of the kind, the equipmentaccording to the invention is designed with respect to desired values ofa media pressure, volume and flowing speed, the said desired valuesbeing initial variable control parameters. The relation betweenco-ordinates of the tridimensional surface of individual parts of themechanism and the said control parameters can be described by a generalmulti-parameter function, the solution of which is a multi-parameter setdefining all possible and therefore even all optimal mechanicalembodiments of the mechanism. The shape of teeth profile and the teethlead in each cross section, reflecting the variability of threedimensions, define volume distribution in relation to desired pressuredistribution and a set of all possible solutions. The final optimalsolution of the mechanism in question is selected form the acquired setof solutions in accordance with limiting depending parameters, such asminimum dimensions with respect to material strength and required outputperformance. The solution according to the invention fully suits todesired values of pressure, volume and velocity of compressed orexpanding media in any part of a working space. It is possible only by asimultaneous change of three dimensional parameters, namely diameters ofrotors, profile and lead of spiral teeth in any particular part of theworking space. In other words the said dimensional parameters aredefined for each point of the working space with respect to selectedvalues of media pressure, volume and velocity in that point. The statorinside surface must of course correspond to rotational wrapper of therotors.

BRIEF DESCRIPTION OF THE DRAWINGS

[0020] By way of examples the invention will be now described withreference to the following drawings:

[0021]FIG. 1a presents two interacting rotors in an axonometric view,showing also a section plane perpendicular to the rotor axis

[0022]FIG. 1b presents the section plane according to FIG. 1a, showingworking space between stator and rotors

[0023]FIG. 2a shows an axonometric view of a housing without rotors in apartial section

[0024]FIG. 2b shows an axonometric view of a stator housing, the housingconstituting substantially a wrapper of rotors

[0025]FIG. 2c shows an axonometric view of a rotor with two spiral teethwound on a rotor surface, the rotor combining concave and convex shapes

[0026]FIG. 3 shows an axonometric view on stator housing furnished withtwo rotors, one of the rotors being in a partial section through spiralteeth

[0027]FIG. 4a shows in a partial section a pair of rotors with a convexsurface and located in a common housing of a compressor application

[0028]FIG. 4b shows a pair of rotors in a partial section along theplane A-A according to FIG. 4a, the rotors being located in a commonhousing

[0029]FIG. 4c shows a pair of rotors with a convex surface in a partialsectional view, the rotors being located in a common housing. Thedirection of the rotor motion and the direction of a media flow areopposite to the situation illustrated in FIGS. 3a, 4 b, thus providingfor an expander application of the equipment

[0030]FIG. 4d shows a pair of rotors in a sectional view along the planeA-A according to FIG. 4c, the rotors being located in a common housing

[0031]FIG. 5a shows a pair of rotors with a concave surface in a partialsectional view, the rotors being located in a common housing of acompressor application,

[0032]FIG. 5b shows a pair of rotors in a partial section along theplane A-A according FIG. 4a, the rotors being located in a commonhousing

[0033]FIG. 5c shows a pair of rotors located in a common housing, in apartial sectional view, one of the rotors having convex surface and theother one a concave surface, the arrangement being designed for anapplication as a compressor,

[0034]FIG. 5d shows a pair of rotors in a common housing, in a sectionalong the plane A-A according to FIG. 5c

[0035]FIG. 5e shows a pair of rotors located in a common housing, in apartial sectional view, the rotors shafts having partially convex andpartially concave surfaces, the said arrangement being designed for acompressor application

[0036]FIG. 5f shows a pair of rotors located in a common housing in asection along the plane A-A according to FIG. 5e

[0037]FIG. 6a shows a pair of rotors running in the same direction ofmotion, in a partial sectional view, the rotor shafts having a concavesurface and the rotors being located in a common housing of a compressorapplication

[0038]FIG. 6b shows a pair of rotors in a partial section along the lineA-A according to FIG. 6a, the rotors being located in a common housing

[0039]FIG. 6c shows a pair of rotors running in an opposite direction ofmotion, in a partial sectional view, the rotor shafts having one spiraltooth

[0040]FIG. 6d shows a pair of rotors located in a common housing in asection along the plane A-A according to FIG. 6c, the tooth profilebeing illustrated

[0041]FIG. 7a shows an equipment with three rotors in a common housing,the middle rotor having a shaft with a convex surface, both side rotorshaving cylindrical shafts

[0042]FIG. 7b shows the three rotors located in a common housing in asection along the plane A-A according to FIG. 7b

[0043]FIG. 8a shows a pair of rotors located in a common housing in asection along the plane A-A according to FIG. 8d

[0044]FIG. 8b shows a pair of rotors located in a common housing in asection along the plane B-B according to FIG. 8d, the tooth profile anda shape of a working space being illustrated

[0045]FIG. 8c shows a pair of rotors located in a common housing in asection along the plane C-C according to FIG. 8d, the tooth profile anda shape of a working space being illustrated

[0046]FIG. 8d shows a pair of rotors running in an opposite direction ofmotion, in a partial sectional view, the rotors being located in acommon housing and the rotor shafts being partially convex and partiallyconcave and having two spiral teeth

[0047]FIG. 8e graphically illustrates a waveform of pressure (P) andvolume (V) within the thread intermediate space according to FIG. 8d,the parts “X”, “Y” and “Z” being a compression, injection—combustion andexpansion sections respectively

[0048]FIG. 9a shows an equipment with three rotors in a common housing,the middle rotor having a shaft with a partially convex and partiallyconcave surfaces and both side rotors cylindrical shafts, the equipmentbeing designed for a motor application

[0049]FIG. 9b shows three rotors located in a common housing in asectional view along the plane B-B according to FIG. 9a

[0050]FIG. 10a shows rotational wrapper of rotors with spiral teethwound on shafts with convex surfaces, the rotors having skewed axes,stator is not shown

[0051]FIG. 10b shows rotational wrapper of rotors with spiral teethwound on shafts with convex surfaces, the rotors having skewed axes, asshown in a plane perpendicular to the view of FIG. 10a and parallel to aplane of rotor axes

[0052]FIG. 11a shows a sectional view of a combination of four rotorsarranged side by side in a common housing,

[0053]FIG. 11b shows a sectional view of a combination of five rotorsarranged side by side in a common housing,

[0054]FIG. 11c shows a sectional view of a combination of five rotors ina star-shape arrangement in a common housing

[0055]FIG. 11d shows a sectional view of a combination of three rotorsin a mutual engagement, the rotors being arranged in a common housing,

[0056]FIG. 11e shows a sectional view of a combination of four rotors ina mutual engagement, the rotors being arranged in a common housing

[0057]FIG. 12 shows a sectional view of a stator with two spiral rotorseach of them provided with spiral teeth wound on shaft surfaces havingconvex shape, the shafts having concurrent axes. The embodiment isdesigned for application as a drive for ships.

DESCRIPTION OF PREFERRED EMBODIMENTS

[0058] On FIG. 1a there is presented an example embodiment of a part ofthe equipment according to the invention. The axonometric view shows twomutually interacting rotors 2,3 and a section plane perpendicular to therotor axis. The section plane of FIG. 1a, as presented in a detail onFIG. 1b, offers a view on working space between stator and rotors, theworking space being depicted by white, non-cross-hatched field withinthe section.

[0059] As further described in details the design according to theinvention suits to desired values of pressure, volume and velocity ofcompressed or expanding media in any part of a working space. Theprincipal dimensional parameters, namely diameters of rotors, profileand lead of spiral teeth are defined for each point of the working spacewith respect to the said operation parameters. The stator 1 insidesurface corresponds to a rotational wrapper of the rotors defined by theabove procedure.

[0060] For a purpose of a clarity of the description and patent claimsthe applied basic terms are defined as follows.

[0061] A concave curve is such a curve, for all points of which itapplies, that the curve at its any section can be expressed by aparameter function, defining a distance of a curve point from theparameter axis, the second derivative of the function to this parameterat this point being always negative or equalling to a zero.

[0062] A convex curve is such curve, for all points of which it applies,that the curve at its any section can be expressed by a parameterfunction, defining a distance of a curve point from the parameter axis,the second derivative of the function to this parameter at this pointbeing always positive or equalling to a zero.

[0063] The parameters of a convex or a concave curve, for which a secondderivative equals zero applies in the case of the invention only forlimit, transit points between adjacent curves.

[0064] A contact curve is a set of points at which there occurs amaximum approach or a mutual contact of surfaces of spiral teeth ofinteracting rotors or contact of surfaces of spiral teeth of interactingrotors with a stator inner wrapper.

[0065] A rotation wrapper is a limiting rotation surface defining aspace of a rotating body all points of which are always only on one sideof this surface and at the same time every point of this surface is apoint through which there passes a rotation track of at least one pointof the rotating body.

[0066] The arrangement of a double rotor equipment shown of FIGS. 1a and1 b is in more details illustrated by axonometric views displayed inFIGS. 2a, 2 b, 2 c. On FIG. 2a there is shown a stator 1, representing ahousing of the equipment. The stator 1 is designed to accommodate tworotors, the first rotor 2 and the second rotor 3 in parallelarrangement. FIG. 2b shows an inner wrapper of the stator 1, the shapeof which is identical with the joint wrapper of rotation wrappers of thefirst rotor 2 and the second rotor 3, which are in an interaction withthe inner wrapper of the stator 1. FIG. 2c shows a view upon a separatefirst rotor 2.

[0067] Another specific embodiment of the technical solution accordingto the invention is presented on FIG. 3. In a partial sectional viewthere is shown the stator 1, representing also the equipment housing,which accommodates two rotors. The first rotor 2, consists of afirst-rotor shaft 21 with a combined concave and convex surfaces, onwhich spiral teeth are wound, the first first-rotor tooth 211 and thesecond first-rotor tooth 211, the teeth being mutually turned by anangle of 180°. The second rotor 3, consists of a second-rotor shaft 31with a combined concave and convex wrappers, on which spiral teeth arewound, namely the first second-rotor tooth 311 and the secondsecond-rotor tooth 311, both teeth being mutually turned by an angle of180°. Both rotors 2,3 have parallel axes, identical profiles of thefirst-rotor teeth 211 and the second-rotor teeth 311 and identical lead,nevertheless the first-rotor teeth 211 have the opposite sense of leadthan the second-rotor teeth 311. Both the first-rotor teeth 211 enterinto the intermediate space of threads of both second-rotor teeth 311,and therefore the first rotor 2 and the second rotor 3 are in a mutualinteraction, engaging especially along contact curves. Rotation tracksof the first-rotor teeth 211 and the second-rotor teeth 311 overlap eachother. The first-rotor teeth 211 divide the opposing intermediate spacesof the threads of the second-rotor teeth 311 and in this way they arecovering them as partition walls and at the same time also thesecond-rotor teeth 311 divide the opposing intermediate spaces of thethreads of the first-rotor teeth 211, covering them as partition walls.An inner space of the stator 1 is limited by a wrapper of a system ofcircles; which are at one hand co-axial with the axis of rotation of thefirst rotor 2 and simultaneously circumscribed to the sum of profiles ofall sections through the first-rotor teeth 211 and at the other handco-axial with the axis of rotation of the second rotor 3 and at the sametime circumscribed to the sum of profiles of all sections through thesecond-rotor teeth 311. As a consequence of the mutual interaction ofthe first rotor 2, the second rotor 3 and the stator 1, threadintermediate spaces are created between the first-rotor teeth 211, thesecond-rotor teeth 311 and the stator 1.

[0068] The equipment according to the specific embodiment of FIG. 3operates in such a way, that by counter rotation of the first rotor 2and the second rotor 3 within the stator 1 the medium entering throughan input into the intermediate space of threads of the first rotor 2 andthe second rotor 3 is moved towards the output. By mutual interaction ofthe first rotor 2 and the second rotor 3 there is performed a mutualpartition of the first rotor 2 thread intermediate space by the secondrotor 2 and vice versa. Due to the combination of a concave and convexshape of the surfaces of the first-rotor shaft 21 and the second-rotorshaft 31, the intermediate space of the threads of the spiralfirst-rotor teeth 211 and the second-rotor teeth 311 decreases with eachsubsequent thread and the medium within the thread intermediate space iscompressed and subsequently with increasing thread intermediate spacesthe medium is expanding.

[0069] In an alternative case, the first-rotor teeth 211 may have thesame sense of lead as the second-rotor teeth 311 and as a consequencethe sense of rotation of both rotors shall be the same. The function ofthe equipment in this case will be substantially the same. The sense ofthe thread lead and mutual engagement of the first-rotor teeth 211 andthe second-rotor teeth 311 impose limitations on possible shapes oftheir profiles and thus on choice of a preferred application of theequipment in a praxis.

[0070] Another particular specific embodiment of the technical solutionaccording to the invention is schematically displayed in a sectionalview on FIGS. 4a, 4 b. In the stator 1, which is the housing of theequipment, the first rotor 2 and the second rotor 3. are seated in apush-fit. The first rotor 2 consists of the first-rotor shaft 21 havinga surface of a convex shape, at which the first spiral first-rotor tooth211 and the second spiral first-rotor tooth 211 are wound, bothfirst-rotor teeth being mutually turned by angle of 180°. The secondrotor 3 consists of the second-rotor shaft 31 having a surface of aconvex shape, at which the first spiral second-rotor tooth 311 and thesecond spiral second-rotor tooth 311 are wound, both second-rotor teethbeing mutually turned by an angle of 180°. The first rotor 2 and thesecond rotor 3 have mutually parallel axes, and both the spiralfirst-rotor teeth 211 and the second-rotor teeth 311 have identicalprofiles and decreasing lead angle, nevertheless the first-rotor teeth211 have the opposite lead sense than the second-rotor teeth 311. Boththe first-rotor teeth 211 inter into the intermediate spaces of threadsof both second-rotor teeth 311, so that the first rotor 2 and the secondrotor 3 are in a mutual interaction, engaging substantially alongcontact curves. Rotation tracks of the first-rotor teeth 211 and thesecond-rotor teeth 311 overlap each other, as displayed by the sectionA-A of FIG. 4b The first-rotor teeth 211 divide opposing intermediatespaces of the threads of the second-rotor teeth 311 thus covering themas partition walls. Simultaneously the second-rotor teeth 311 divideopposing intermediate spaces of the threads of the first-rotor teeth211, thus also covering them as partition walls. The inner space of thestator 1 is limited by a rotation wrapper of the first rotor 2 and atthe same time by a rotation wrapper of the second rotor 3. In thisparticular embodiment the inlet is on the side of the maximum mutualoverlapping of the first rotor 2 and the second rotor 3, while theequipment outlet is on the opposite side, manifesting minimal mutualoverlapping of both rotors 2, 3. FIG. 4b displays the first rotor 2 andthe second rotor 3 with preferred profiles of the spiral first-rotorteeth 211 and the second-rotor teeth 311, both engaging rotors beingshown as viewed in a plane perpendicular to the axes of rotation of therotors 2, 3.

[0071] The equipment according to the specific embodiment of FIGS. 4aand 4 b operates in such a way, that by counter rotation of the firstrotor 2 and the second rotor 3 within the stator 1 the medium enteringthrough an input into the intermediate space of threads of the firstrotor 2 and the second rotor 3 is moved towards the output. By mutualinteraction of the first rotor 2 and the second rotor 3 there isperformed a mutual partition of the first rotor 2 thread intermediatespace by the second rotor 2 and vice versa. Due to the convex shape ofthe surfaces of the first-rotor shaft 21 and the second-rotor shaft 31,the intermediate space of the threads of the first-rotor teeth 211 andthe second-rotor teeth 311 decreases with each subsequent thread and themedium within the thread intermediate space is compressed.

[0072] The equipment according to the specific embodiment of FIG. 4c hasthe same arrangement as the embodiment according to FIGS. 4a, 4 b, onlythe first rotor 2 rotates in a direction opposite and the sense ofrotation of the second rotor 3. The medium inlet is on the side of theequipment with the minimum mutual overlapping of the first rotor 2 andthe second rotor 3 and the equipment outlet of is on the opposite side,manifesting maximum mutual overlapping of the first and second rotors 2,3. As a consequence of the convex shape of the surfaces of both thefirst-rotor shaft 21 and the second-rotor shaft 31, the threadintermediate spaces of the first rotor 2 and the second rotor 3 increasewith each subsequent thread and the medium within the threadintermediate spaces is expanding. This allows for an expansion functionof this specific embodiment of the equipment.

[0073] Another particular specific embodiment of the technical solutionaccording to the invention is schematically displayed in a sectionalview on FIGS. 5a, 5 b, the latter one showing a sectional view A-Aaccording to FIG. 5a. In the stator 1, which is the housing of theequipment, there are in a push fit seated the first rotor 2 and thesecond rotor 3. The first rotor 2 consists of the first-rotor shaft 21having a surface of a concave shape, at which the first spiralfirst-rotor tooth 211 and the second spiral first-rotor tooth 211 arewound, both first-rotor teeth 211 being mutually turned by an angle of180°. The second rotor 3 consists of the second-rotor shaft 31 having asurface of a concave shape, at which the first spiral second-rotor tooth311 and the second spiral second-rotor tooth 311 are wound, bothsecond-rotor teeth 311 being mutually turned by an angle of 180°. Thefirst rotor 2 and the second rotor 3 have axes arranged in parallel, andboth the spiral first-rotor teeth 211 and the second-rotor teeth 311have identical profiles and decreasing lead angle, but the spiralfirst-rotor teeth 211 have the opposite lead sense than the spiralsecond-rotor teeth 311. Both first-rotor teeth 211 inter into theintermediate spaces of threads of both spiral second-rotor teeth 311, sothat the first rotor 2 and the second rotor 3 are in a mutualinteraction, engaging substantially along contact curves. Rotationtracks of the spiral first-rotor teeth 211 and the second-rotor teeth311 overlap each other, as displayed on the section A-A of FIG. 5b Thefirst-rotor teeth 211 divide opposing intermediate spaces of the threadsof the second-rotor teeth 311 thus covering them as partition walls.Simultaneously also the second-rotor teeth 311 divide opposingintermediate spaces of the threads of the first-rotor teeth 211, thusalso covering them as partition walls. The inner space of the stator 1is limited by a rotation wrapper of the first rotor 2 and at the sametime by a rotation wrapper of the second rotor 3. In this particularembodiment the inlet is on the side of the maximum mutual overlapping ofthe first rotor 2 and the second rotor 3, while the equipment outlet ison the opposite side, manifesting minimum mutual overlapping of bothrotors 2, 3. FIG. 5b displays the first rotor 2 and the second rotor 3with preferred profiles of the first-rotor teeth 211 and thesecond-rotor teeth 311, both engaging rotors being shown as viewed in aplane perpendicular to the axes of the rotor rotation. From the point ofview of function the embodiment of FIGS. 5a and 5 b offers a workingcharacteristics of a media compression having a steeper waveform thanapplies for the embodiment of FIGS. 4a, 4 b.

[0074] Another particular specific embodiment of the technical solutionaccording to the invention as schematically displayed in a sectionalview on FIGS. 5c and 5 d, is equivalent to the embodiment of FIGS. 5aand 5 b. It differentiates from the previous one by the shape of shaftsurfaces as the first-rotor shaft 21 surface has a convex shape whilethe second-rotor shaft 31 surface is concave. This shapes result inrather different shapes of the first rotor 2 and the second rotor 3 andtheir rotation wrappers, defining an inner space of the stator 1. Otherparameters, arrangement and mutual interactions of elements of thespecific embodiment displayed at FIGS. 5c, 5 d correspond to theembodiment of FIGS. 5a, 5 b. Its function is analogous to the previousspecific embodiments of FIGS. 4a, 4 b and 5 a, 5 b. The difference is tobe seen in the fact that the equipment according to this specificembodiment, combining the first-rotor shaft 21 with a concave surfaceand the second-rotor shaft 31 with a convex surface within the stator 1,has unequal thread intermediate spaces of the first-rotor teeth 211 andthe second-rotor teeth 311, the difference resulting from the differentrotor rotation wrappers. As a consequence of this arrangement a changeof the thread intermediate space has steeper characteristic than it isby the equipment with the first-rotor shaft 21 and the second-rotorshaft 31 having convex surfaces, as displayed on FIGS. 4a, 4 b, but notsuch a steep characteristic as the equipment with the first-rotor shaft21 and the second-rotor shaft 31 having concave surfaces, as displayedon FIGS. 5a, 5 b. This applies only when provided that profiles, leadand numbers of spiral teeth are substantially identical.

[0075] Another particular specific embodiment of the technical solutionaccording to the invention as schematically displayed in a sectionalview on FIGS. 5e, 5 f, is equivalent to the embodiment of FIGS. 5a and 5b. It differentiates from the previous one by the shape of shaftsurfaces as both the first-rotor shaft 21 surface and the second-rotorshaft 31 surface have partially convex and partially concave shape, bothsurfaces being mutually identical. This shapes result in ratherdifferent shapes of the first rotor 2 and the second rotor 3 and theirrotation wrappers, defining an inner space of the stator 1. Otherparameters, arrangement and mutual interactions of elements of thespecific embodiment displayed on FIGS. 5e, 5 f correspond to theembodiment of FIGS. 5a, 5 b. This embodiment combines features of thesolution according FIGS. 4a and 4 b, with features of the embodimentaccording FIGS. 5a, 5 b and allows for more favourable waveform of theoperation characteristic of media compression. In the inlet part of theequipment, within thread intermediate spaces, due to the high profile ofspiral teeth of both the first and second rotors 2, 3, there istransported high, constant volume of the medium. In the middle part themedium is continuously compressed and in the outlet part, due to thehigher number of teeth with a low profile of the spiral teeth, a closureof an outlet opening is improved, and a return flow of the medium withinthe equipment is prevented.

[0076] A change of a shape of the convex or concave wrappers of thefirst-rotor shaft 21 and the second-rotor shaft 31 and/or a change oflead of the first-rotor teeth 211 and the second-rotor teeth 311,results in a decrease and/or increase of the volume of intermediatespaces of threads of the first rotor 2 and the second rotor 3. Thisapplies for any part of the first rotor 2 and the second rotor 3.

[0077] Other particular embodiment of the technical solution accordingto the invention is displayed at FIGS. 6a, 6 b. The spiral first-rotorteeth 211 have the same sense of lead as the spiral second-rotor teeth311. As a consequence, the sense of rotation of both rotors 2, 3 is thesame. The sense of lead and the mutual engagement of the first-rotorteeth 211 and the second-rotor teeth 311, are limiting factors foravailable shapes of profiles of the spiral first-rotor teeth 211 and thesecond-rotor teeth 311, as displayed at FIG. 6b and thus also for aparticular application the equipment function. The equipment function issubstantially the same as applies for the equipment of FIGS. 4a, 4 b,but different profiles of the spiral rotating teeth allow for adifferent waveform of working characteristics of the equipment anddifferent practical application. By opposite sense of rotation of boththe first rotor 2 and the second rotor 3, the equipment will work as anexpander.

[0078] Another particular solution is the embodiment displayed on FIGS.6c, 6 d having a first rotor 2 with one spiral first-rotor tooth 211wound on the first-rotor shaft 21 and a second rotor 3 with one spiralsecond-rotor tooth 311 wound on a second-rotor shaft 31. This embodimentallows for a choice from a wider variety of profiles of the spiralfirst-rotor tooth 211 and the second-rotor tooth 311 and for furtheralternative process of the medium compression in thread intermediatespaces. According to the sense of rotation of both rotors 2, 3 theequipment operates either as a compressor or as an expander.

[0079] Another alternative solution is an equipment having the firstrotor 2 with one spiral first-rotor tooth 211 wound on a first-rotorshaft 21 and further having a second rotor 3 with several spiralsecond-rotor teeth 311 wound on a second-rotor shaft 31. This embodimentlimits the profile spectrum of spiral rotors teeth and the equipmentfunction is subjected to unequal revolutions of the first rotor 2 andthe second rotor 3, which could be favourable for special procedures ofmedium compression. The first rotor 2 with one first-rotor tooth 211 canfor example function as a partition wall, like a spiral slide valve andthe second rotor 3 with several spiral second-rotor teeth 311 does theworking function, or the other way round.

[0080] All the above presented particular solutions and alternativescould be modified by different diameters of the rotation wrappers ofrotors. This can advantageously allow for different mode of operation ofthe equipment according to the invention.

[0081] Each of the mentioned specific embodiments can be also operatedin a reverse mode, with reversed direction of rotation of the rotors. Incases when the thread intermediate space moves from an inlet to anoutlet, its volume increasing simultaneously, as is the case of theembodiment according to FIGS. 4c, 4 d, the equipment functions as anexpander. Such a function may be utilised for a transfer of the mediumpower in a rotation movement of rotors. Another application is suitablefor an equipment utilising a decrease of pressure acting upon a mediumduring pumping process, e.g. in a case when media must not be pumpedunder pressure.

[0082] Another preferred specific embodiment is displayed in a sectionalviews on FIGS. 7a and 7 b. In the stator 1 there are seated the firstrotor 2, the second rotor 3 and a fourth rotor 4, all rotors 2,3,4 beingin a mutual interaction. The first rotor 2 comprise a first-rotor shaft21 having a surface of a convex shape, at which two spiral first-rotorteeth 211 are wound, both first-rotor teeth 211 being mutually turned byan angle of 180°. The second rotor 3 consists of a second-rotor shaft 31having a surface of a cylindrical shape, at which two spiralsecond-rotor teeth 311 are wound, both second-rotor teeth 311 beingmutually turned by an angle of 180°. The third rotor 4 has a third-rotorshaft 41 with a surface of a cylindrical shape, at which two spiralthird-rotor teeth 411 are wound, both third-rotor teeth 411 beingmutually turned by an angle of 180°. Axes of all three rotors 2, 3, 4are arranged in parallel and in the same plane. The first rotor 2 islocated between the third rotor 3 and the fourth rotor 4 and has itsspiral first-rotor teeth 211 wound with the opposite sense than both thethird rotor 3 and the fourth rotor 4 and profiles of his first-rotorteeth 211 define not only the second-rotor teeth 311 and the third-rotorteeth 411 but also a shape of the stator 1 inner surface. Both thesecond rotor 3 and the third rotor 4 are identical. They have identicalprofiles of all their second-rotor teeth 311 and the third-rotor teeth411, the said teeth 311,411 having also identical sense of lead and leadangles, the angle decreasing in the direction from inlet to outlet ofthe equipment. The inlet side of the equipment is the side with thesmallest diameter of the convex wrapper of the first-rotor shaft 21,while the outlet side manifests the same diameter being the largest one.The first-rotor teeth 211 enter the intermediate spaces of threads ofboth the second-rotor teeth 311 and third-rotor teeth 411, in aninteraction with them, the said mutual engagement being performedsubstantially along contact curves. Rotation tracks of the spiralfirst-rotor teeth 11 and the second-rotor teeth 311 overlap each otherand the same applies for the first-rotor teeth 211 and the third-rotorteeth 411, as shown on FIG. 7a. The first-rotor teeth 211 divideopposing intermediate spaces of the threads of both the second-rotorteeth 311 thus covering them as partition walls. Simultaneously thesecond-rotor teeth 311 and the third-rotor teeth 411 divide opposingintermediate spaces of the threads of the first-rotor teeth 211, thusalso covering them as partition walls. The inner space of the stator 1is defined by rotation wrappers of all three rotors 2, 3, 4. FIG. 7billustrates mutual interaction of the three rotors 2, 3, 4 with thefirst-rotor teeth 211, the second-rotor teeth 311 and the third-rotorteeth 411, as seen in a sectional plane perpendicular to axes ofrotation of the said rotors2, 3, 4, the said teeth 211, 311, 411 havingpreferred profiles.

[0083] The equipment according to the specific embodiment of FIGS. 7aand 7 b operates in such a way, that by counter rotation of the firstrotor 2 with respect to the second rotor 3 and the third rotor 4 amedium entering through an input into the intermediate space of threadsof all three rotors 2, 3, 4 is moved towards the output. By mutualinteraction of the three rotors 2, 3, 4 there is performed a mutualpartition of the first rotor 2 thread intermediate space by the secondrotor 3 and vice versa and simultaneously there occurs a mutualpartition of the first rotor 2 thread intermediate space by the thirdrotor 4 and vice versa. Due to the convex shape of the surfaces of thefirst-rotor shaft 21, the thread intermediate decreases with eachsubsequent thread and the medium within the thread intermediate spacesis compressed. In this embodiment the equipment operates as acompressor. In an alternative case, with a sense of rotation of therotors 2, 3, 4 being opposite to the one described above, the equipmentshall operate as an expander.

[0084] In all the specific embodiments of the equipment designed foroperation either as a compressor or as an expander, the stator may bealternatively furnished with rotors having concurrent axes. Thisarrangement shall result in a steeper waveform of operationcharacteristics of such an equipment.

[0085] Another preferred specific embodiment is displayed on FIGS. 8a, 8b, 8 c, 8 d. FIG. 8e shows waveforms of pressure and volume in threadintermediate space relating to this embodiment. In the stator 1, whichrepresenting also a housing of the equipment, the are seated the firstrotor 2 and the second rotor 3. The first rotor 2 comprises thefirst-rotor shaft 21, the surface of which within sections X and Z, asseen on FIG. 8d, has a convex shape, while within a section Y it has aconcave shape. On the first-rotor shaft 21 two spiral first-rotor teeth211 are wound, both first-rotor teeth 211 being mutually turned by anangle of 180°. The second rotor 3 consists of a second-rotor shaft 31,the surface of which within the sections X and Z, see FIG. 8d, has aconvex shape, while within the section Y it has a concave shape. On thissurface two spiral second-rotor teeth 311 are wound, both second-rotorteeth 311 being mutually turned by an angle of 180°. Both rotors 2, 3,have parallel axes and substantially identical profiles of all thefirst-rotor and second-rotor teeth 211, 311. The teeth 211, 311 leadangle is decreasing within the section X, while remaining constantwithin the section Y and increasing within the section Y. Diameter of arotation wrapper of the first rotor 2 and the second rotor, 3, isincreasing within the section X in the direction inwards from the inlet,while having substantially minimum value within the section Y andincreasing within the section Z along the direction towards the outlet,where it reaches its maximum value. The first-rotor teeth 211 have leadwith a sense opposite to the one of the second-rotor teeth 311. Bothfirst-rotor teeth 211 enter into the intermediate spaces of threads ofboth second-rotor teeth 311, providing for an interaction of both rotors2,3, their mutual engagement being performed substantially along contactcurves. Rotation tracks of the spiral first-rotor teeth 211 and thesecond-rotor teeth 311 overlap each. The spiral first-rotor teeth 211divide opposing intermediate spaces of the threads of the second-rotorteeth 311 thus covering them as partition walls. Simultaneously thesecond-rotor teeth 311 divide opposing intermediate spaces of thethreads of the first-rotor teeth 211, thus also covering them aspartition walls. The inner space of the stator 1 is limited by rotationwrappers of both rotors 2, 3. In this embodiment the equipment may workas an internal combustion engine. A medium enters through inlet in thesection X, which operates as a compression chamber of the engine. Thesection Y operates as an injection and ignition area and the section Zrepresents an expansion space of the motor completed with the outlet.

[0086] The combustion engine according to the specific embodiment ofFIGS. 8a, 8 b, 8 c, 8 d operates in such a way, that by a counterrotation of the first rotor 2 and the second rotor 3 within the stator 1air is sucked through an input and moved into the intermediate space ofthreads of the first-rotor teeth 211 and the second-rotor teeth 311. Inthe X section, due to the convex shape of surfaces of both thefirst-rotor shaft 21 and the second-rotor shaft 31 and the respectiveshape of the stator 1 inside surface the air is compressed. Within the Ysection fuel is injected into the compressed air and ignited. Throughoutthe Z section the burning fuel expands and its pressure energy actswithin thread intermediate spaces of the rotors 2,3 upon surfaces of thefirst-rotor teeth 211 and the second-rotor teeth 311 and the actionresults in a torque of the rotors 2,3. The outlet is the motor exhaust.

[0087] On FIG. 8e a curve depicted as “V-curve” represents changes ofvolume, while the other curve, the “P-curve”, represents changes ofpressure within the individual sections “X”, “Y”, “Z” of the motor.

[0088] In an alternative case of the combustion engine, the first-rotorteeth 211 may have the same sense of lead as the spiral second-rotorteeth 311 and in consequence of this both rotors 2,3 must the same senseof rotation. The function of such combustion engine is substantially thesame. The lead sense and mutual engagement of the first-rotor teeth 211and the second-rotor teeth 311 is a limiting factor for shapes ofprofiles of the spiral teeth 211, 311 and therefor also for practicalapplications of such a combustion engine.

[0089] In further alternative embodiments of the combustion engine, theconvex surfaces of first-rotor shaft 21 and second-rotor shaft 31 insection X,Z may be changed into a concave one while the surface of theshafts 21, 31 within the section Y has a convex shape. The surface ofthe shafts 21, 31 may even be of a cylindrical or a tapered shape.

[0090] Still further specific embodiment of the equipment according tothe invention is schematically shown on FIGS. 9a and 9 b. In stator 1there are seated three rotors, a first rotor 2, a second rotor 3 and athird rotor 4, all three rotors being in a mutual interaction, theiraxes being located in one and the same plane. The arrangement of therotors 2, 3, 4 correspond substantially to the embodiment shown on FIGS.7a, 7 b. A part of the equipment, which on FIG. 9a is depicted as an“M-section”, corresponds to the construction of FIG. 7a, designed forcompressor application. The adjacent part of the equipment following the“M-section”, on FIG. 9 depicted as an “N-section”, corresponds to theconstruction of FIG. 7a, but in an alternative, expander application.

[0091] The function is similar to the one applying for the specificembodiment of FIGS. 8a, 8 b, 8 c, 8 d. The equipment therefore operatesalso as a combustion engine. The injection and ignition area correspondsto the area of transition of the “M-section” into the “N-section”.

[0092] Further specific embodiment of the equipment according to theinvention is schematically presented on FIGS. 10a, 10 b, which for sakeof clarity and understandability show only the first rotor 2 and thesecond rotor 3, without the stator 1. Displayed there are also onlyrotation wrappers of the first-rotor teeth 211 and the second-rotorteeth 311. This equipment being equivalent to the one shown on FIGS. 8a,8 b, 8 c and 8 d, is also a combustion engine. The only difference is,that the axis of the first rotor 2 and the axis of the second rotor 3are skew lines. This particular embodiment allows for steep workingcharacteristic of the engine. In alternative cases of skew rotor axisarrangement the equipment could be operated also as a compressor and/orexpander, again with the advantage of very steep workingcharacteristics.

[0093]FIGS. 11a, 11 b, 11 c, 11 d and 11 e schematically display severalexamples of mutual arrangement of the first rotors 2, the second rotors3 and the stators 1 of the equipment described above. There exists avariety of other combinations, which could be applied according toparticular requirements on the equipment functions. FIG. 11a presents aside-by-side arrangement of the first rotors 2 and the second rotor 3,their axes being parallel. FIGS. 11b, 11 c show a star-shape arrangementof one first rotor 2 and multiple second rotors 3 seating in the stator1. FIG. 11d illustrates an alternative arrangement of three first rotors2 in the stator 1, where all three first rotors 2 are in a mutuallyengagement and therefore must have the same sense of rotation. FIG. 11erepresents another alternative arrangement of two first rotors 2 and twosecond rotors 3 in the stator 1, where each rotor engages with twoadjacent rotors 2, 3.

[0094] The last but not least preferred embodiment of the technicalsolution according to the invention is schematically shown on FIG. 12.In the stator 1, which is also a housing of the equipment, there areseated the first rotor 2 and the second rotor 3. The first rotor 2consists of the first-rotor shaft 21 with a convex surface, on whichthere are wound-up the first spiral first-rotor tooth 211 and the spiralsecond first-rotor tooth 211, both teeth 211 being mutually shifted bythe angle of 180°. The second rotor 3 consists of the second-rotor shaft31 with a convex surface, on which there are wound-up the first spiralsecond-rotor tooth 311 and the second spiral second-rotor tooth 311,both teeth 311 being mutually shifted by angle of 180°. Both the firstrotor 2 and the second rotor 3, have concurrent axis, mutually identicalprofiles of all first-rotor teeth 211 and second-rotor teeth 311, withlead angle increasing from the inlet side towards the outlet side,provided the volume of thread intermediate spaces is constant. Thefirst-rotor teeth 211, have the opposite sense of lead than thesecond-rotor teeth 311. Both first-rotor teeth 211 enter into theintermediate spaces of the threads of both second-rotor teeth 311, therotors engaging substantially along the contact curves. The rotationtracks of the first-rotor teeth 211 and the second-rotor teeth 311overlap each other. The first-rotor teeth 211 divide the oppositeintermediate spaces of the threads of the second-rotor teeth 311 thussubstantially closing them as partition walls. At the same time thesecond-rotor teeth 311 divide the opposite intermediate spaces of thethreads of the first-rotor teeth 211 thus substantially closing them aspartition walls. The inner space of stator 1 is limited by a rotatingwrapper of the first rotor 2 and also by a rotating wrapper of thesecond rotor 3. In this embodiment the inlet of the equipment on theside with maximum mutual overlapping of the first rotor 2 and the secondrotor 3 and the distance between their rotation axis being the largestone. The outlet of the equipment is at the opposite side, with minimummutual overlapping of the rotors and smallest distance of their rotationaxis.

[0095] The equipment according to the specific embodiment of FIG. 12operates in such a way, that by counter rotation of the first rotor 2and the second rotor 3 within the stator 1 the medium enters through aninput into the intermediate space of threads of the first rotor 2 andthe second rotor 3 and is moved towards the output. By mutualinteraction of the first rotor 2 and the second rotor 3 there isperformed a mutual partition of the first rotor 2 thread intermediatespace by the second rotor 2 and vice versa. Due to the convex shape ofthe surfaces of the first-rotor shaft 21 and the second-rotor shaft 31and increasing angle of lead of both the first-rotor teeth 211 and thesecond-rotor teeth 311, their thread intermediate spaces are changing inshape but remain constant in volume. Speed of the medium transferthrough the thread intermediate space accelerates along the directionfrom the inlet towards the outlet. Such an embodiment is suitable as adriving gear for ships.

[0096] By all the above-mentioned preferred embodiments, except theequipment with only one spiral tooth or only one rotor, it is possibleto wind up the spiral teeth alternatively on surface of shafts with amutual irregular angle shift. It shall require a change of profiles ofthe spiral teeth, designed by known methods, to achieve mutualinteraction between the rotors themselves and the rotors with respect tothe stator.

[0097] It is also possible to wind up a higher number of spiral teeth ona shaft surface. Nevertheless it shall also require a change of profilesof the spiral teeth, designed by known methods, to achieve mutualinteraction between the rotors themselves and the rotors with respect tothe stator. It can be advantageous for an effective action of a mediumwithin thread intermediate spaces, for a strength of the material ofspiral teeth and for efficiency of the equipment. It is also possible tomanufacture variants with different number of spiral teeth wound-up onindividual parts of the surface of the same shaft.

[0098] Another variety of above-mentioned equipment may compriseembodiments with rotors divided in a plane perpendicular to the axis oftheir rotation, the rotors being mutually interconnected by gears. Theadvantage of such variations would include a possibility of a change ofworking characteristics of particular equipment and a continuous andsmooth control of the operation.

[0099] From the above mentioned examples of specific embodiments, theiralternatives and variations it is evident, that the basic invention ideaand the invention step comprise the solution enabling to combine at thesame time changes of all parameters of spiral teeth in mutualinteraction, concavity and/or convexity of the rotor shaft surfaces andthe inner stator surfaces. Each section of the thread intermediate spaceof the equipment according to the invention could be really differentand in any place of the rotor it is possible to change at the same timeall three parameters, namely the diameter, the sense of lead and theangle of lead of the spiral teeth.

INDUSTRIAL APPLICATIONS

[0100] The present invention is designed for many industrial branchesand fields. It can be applied especially everywhere, where compressorsand turbo-compressors, expanders, exhausters, combustion engines, steamor gas engines and turbines, hydro-motors, hydro-generators, pump,mixing equipment and spiral drives of ships are used.

1. An equipment with mutually interacting spiral teeth, comprising atleast two spiral rotors seating in a stator, where at least a part of arotation wrapper of each of the rotors and corresponding parts of thestator inner surface and the other rotor shaft surface are created by arotation of a curve having a convex or concave shape, wherein surfacesof the rotor shafts, a rotation wrapper of each of the rotors, each onebeing furnished with at least one spiral tooth, and a shape of thestator inner surface are created by a rotation of a combination ofcurves having convex and/or concave shape, the curve waveform beingdefined by shapes of the spiral teeth profiles and their thread lead,provided the spiral teeth profiles and their thread lead as presented inany section perpendicular to a longitudinal axis of the rotorscorrespond to required values of pressure, volume and velocity of amedia in any part of a working space within the section, the workingspace being defined as an intermediate space between respective spiralrotors themselves and between the rotors and the stator, while thespiral teeth manifest leads of the same or opposite sense.
 2. Theequipment according to claim 1, wherein the axis of shafts of the spiralrotors are located in one plane.
 3. The equipment according to claim 1,wherein the axis of shafts of the spiral rotors are mutually skewed. 4.The equipment according to claim 1, wherein the rotation curve in atleast one of its parts comprise a convex curve, while at least in one ofthe remaining parts it is of a concave type.
 5. The equipment accordingto claim 2, wherein the rotation curve in at least one of its partscomprise a convex curve, while at least in one of the remaining parts itis of a concave type.
 6. The equipment according to claim 3, wherein therotation curve in at least one of its parts comprise a convex curve,while at least in one of the remaining parts it is of a concave type.